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<title>Problem 2101. -- [Usaco2010 Dec]Treasure Chest -- 衡阳八中OJ离线版-2012-02-29</title><center><h2>2101: [Usaco2010 Dec]Treasure Chest</h2><span class=green>Time Limit: </span>10 Sec&nbsp;&nbsp;<span class=green>Memory Limit: </span>64 MB<br><span class=green>Submit: </span>136&nbsp;&nbsp;<span class=green>Solved: </span>57<br>[<a href='submitpage.php?id=2101'>Submit</a>][<a href='problemstatus.php?id=2101'>Status</a>][<a href='bbs.php?id=2101'>Discuss</a>]</center><h2>Description</h2><div class=content>Bessie and Bonnie have found a treasure chest full of marvelous
gold coins! Being cows, though, they can't just walk into a store and
buy stuff, so instead they decide to have some fun with the coins.

The N (1 <= N <= 5,000) coins, each with some value C_i (1 <= C_i
<= 5,000) are placed in a straight line. Bessie and Bonnie take turns,
and for each cow's turn, she takes exactly one coin off of either
the left end or the right end of the line. The game ends when there
are no coins left.

Bessie and Bonnie are each trying to get as much wealth as possible for
themselves. Bessie goes first. Help her figure out the maximum
value she can win, assuming that both cows play optimally.

Consider a game in which four coins are lined up with these values:

            30  25  10  35

Consider this game sequence:

                           Bessie    Bonnie       New Coin
Player   Side   CoinValue   Total     Total         Line
Bessie   Right     35        35         0       30  25  10
Bonnie   Left      30        35        30         25  10
Bessie   Left      25        60        30           10
Bonnie   Right     10        60        40           --

This is the best game Bessie can play.

两个人取石子，只能从左右端点取，两人最优策略，问Bessie最多能拿多少石子
</div><h2>Input</h2><div class=content>* Line 1: A single integer: N

* Lines 2..N+1: Line i+1 contains a single integer: C_i

</div><h2>Output</h2><div class=content>* Line 1: A single integer, which is the greatest total value Bessie
        can win if both cows play optimally.
</div><h2>Sample Input</h2>
			<div class=content><span class=sampledata>4<br />
30<br />
25<br />
10<br />
35<br />
<br />
</span></div><h2>Sample Output</h2>
			<div class=content><span class=sampledata>60<br />
<br />
</span></div><h2>HINT</h2>
			<div class=content><p>求翻译.........站内PM我吧.........</p></div><h2>Source</h2>
			<div class=content><p><a href='problemset.html?search=Silver'>Silver</a></p></div><center>[<a href='submitpage.php?id=2101'>Submit</a>][<a href='problemstatus.php?id=2101'>Status</a>][<a href='bbs.php?id=2101'>Discuss</a>]</center>﻿<br>

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